NCC 2019 Volume Two
1.4 Design scenarios: NCC Performance Requirements

1.4 Design scenarios: NCC Performance Requirements

This Verification Method presents specific design scenarios that must be considered in order to demonstrate that the fire safety aspects of a building design comply with the fire safety Performance Requirements set out in Table 1.1.

The design scenarios specified in Section 2 are summarised in Table 1.1.

<b>Table 1.1 Key features of design scenarios</b>

Design scenario

Performance Requirement Note 1

Outcome required Note 3

Typical method or solution

BE

Fire blocks evacuation route(2.1).

[A fire blocks an evacuation route]

CP1, CP2, CP3, CP8, DP4, DP5, DP6, DP7Note 2, EP1.4, EP2.1, EP2.2, EP4.1, EP4.2, EP4.3

Demonstrate that the level of safety is at least equivalent to the Deemed-to-Satisfy Provisions.

Demonstrate that a viable evacuation route (or multiple evacuation routes where necessary) has been provided for building occupants.

UT

Fire in a normally unoccupied room threatens occupants of other rooms (2.2).

[A fire starts in a normally unoccupied room and can potentially endanger a large number of occupants in another room]

CP1, CP2, CP3, CP8, DP4, DP5, EP1.4, EP2.1, EP2.2, EP4.1, EP4.2, EP4.3

Demonstrate that the level of safety is at least equivalent to the Deemed-to-Satisfy Provisions.

ASET / RSET analysis or provide separating construction or fire suppression complying with a specified Standard.

Solutions might include the use of separating elements or fire suppression to confine the fire to the room of origin.

CS

Fire starts in concealed space (2.3).

[A fire starts in a concealed space that can facilitate fire spread and potentially endanger a large number of people in a room]

CP1, CP2, CP3, CP6, CP8, DP4, DP5, DP6, EP1.4, EP2.1, EP2.2, EP4.1, EP4.2, EP4.3

Demonstrate that fire spread via concealed spaces will not endanger occupants; and

Demonstrate that the level of safety is at least equivalent to the Deemed-to-Satisfy Provisions.

Solutions might include providing separating construction or fire suppression or automatic detection complying with a specified Standard.

SF

Smouldering fire (2.4).

[A fire is smouldering in close proximity to a sleeping area]

CP2, CP3, CP8, DP4, DP5, DP6, EP1.1, EP1.2, EP1.3, EP1.4, EP2.1, EP2.2, EP4.1, EP4.2, EP4.3

Demonstrate that the level of safety is at least equivalent to the Deemed-to-Satisfy Provisions.

Solutions might include providing automatic detection and alarm system complying with a recognised Standard.

HS

Horizontal fire spread (2.5).

[A fully developed fire in a building exposes the external walls of a neighbouring building]

CP2

Demonstrate that the risk of fire spread between buildings is not greater than buildings complying with the Deemed-to-Satisfy Provisions.

CV1, CV2.

VS

Vertical fire spread involving cladding or arrangement of openings in walls (2.6).

[A fire source exposes a wall and leads to significant vertical fire spread]

CP2, CP4, CP7, CP8, EP2.2

Demonstrate that the building’s external cladding / facade and arrangement of openings in the building do not increase the risk to life resulting from a fire beyond that for a similar building complying with the Deemed-to-Satisfy Provisions.

CV3.

IS

Fire spread involving internal finishes (2.7).

[Interior surfaces are exposed to a growing fire that potentially endangers occupants].

CP2, CP4, DP4, DP5, DP6, EP1.1, EP1.4, EP2.1, EP2.2, EP4.1, EP4.2, EP4.3

Maintain tenable conditions to allow time for evacuation of occupants and to facilitate fire brigade intervention; and

Demonstrate that the level of safety is at least equivalent to the Deemed-to-Satisfy Provisions.

ASET / RSET analysis or equivalent growth and species production rates.

FI

Fire brigade intervention (2.8).

[Consider fire brigade intervention]

CP1, CP2, CP5, CP7, CP9, DP5, EP1.3, EP1.6, EP2.2, EP3.2

Demonstrate consideration of potential fire brigade intervention; and

Demonstrate that the level of safety is at least equivalent to the Deemed-to-Satisfy Provisions.

Facilitate fire brigade intervention to the degree necessary.

UF

Unexpected Catastrophic Failure (2.9).

[A building must not unexpectedly collapse during a fire event]

CP1, CP2, CP9

Demonstrate that the building, its critical elements and the fire safety system provide sufficient robustness such that unexpected catastrophic failure is unlikely; and

Demonstrate that the level of safety is at least equivalent to the Deemed-to-Satisfy Provisions.

Undertake review or risk assessment of critical elements within a building to determine unexpected catastrophic failure is unlikely.

CF

Challenging fire (2.10).

[Worst credible fire]

CP1, CP2, CP3, CP8, DP4, DP5, DP6, EP1.1, EP1.2, EP1.3, EP1.4, EP2.1, EP2.2, EP4.1, EP4.2, EP4.3

Demonstrate that the level of safety is at least equivalent to the Deemed-to-Satisfy Provisions.

ASET / RSET analysis.

RC

Robustness check (2.11).

[Failure of a critical part of the fire safety systems will not result in the design not meeting the Objectives of the BCA]

CP1, CP2, CP3, CP8, DP4, DP5, DP7Note 2, EP1.1, EP1.2, EP1.3, EP1.4, EP2.1, EP2.2, EP4.1, EP4.2, EP4.3

Demonstrate that if a key component of the fire safety system fails, the design is sufficiently robust that a disproportionate spread of fire does not occur (e.g. ASET/ RSET for the remaining floors or fire compartments is satisfied); and

Demonstrate that the level of safety is at least equivalent to the Deemed-to-Satisfy Provisions.

Modified ASET / RSET analysis.

SS

Structural Stability and other properties (2.12).

[Building does not present risk to other properties in a fire event]

CP1, CP5

Demonstrate that the building does not present an unacceptable risk to other property due to collapse or barrier failure resulting from a fire; and

Demonstrate that the level of safety is at least equivalent to the Deemed-to-Satisfy Provisions.

Undertake analysis of structure and fire safety systems.

Notes to Table 1.1 :

  1. Not all of these requirements will always be applicable to this design scenario. The project specific Performance Requirements must be determined as part of the performance-based design brief process.
  2. Appropriate analysis of DP7 is also required where a lift is intended to be used to assist occupants to evacuate.
  3. When required to demonstrate that the level of safety is at least equivalent to the Deemed-to-Satisfy Provisions refer to Clause 1.3.1.3.
Performance Requirement Design scenario
CP1 BE, UT, CS, FI, UF, CF, RC, SS
CP2 BE, UT, CS, SF, HS, IS, FI, CF, RC, UF, VS
CP3 BE, UT, CS, SF, CF, RC
CP4 IS, VS
CP5 FI, SS
CP6 CS
CP7 FI, VS
CP8 BE, UT, CS, SF, CF, RC, VS
CP9 FI, UF
DP4 BE, UT, CS, SF, IS, CF, RC
DP5 BE, UT, CS, SF, IS, FI, CF, RC
DP6 BE, CS, SF, IS, CF, RC
DP7 BE, RC
EP1.1 SF, IS, CF, RC
EP1.2 SF, CF, RC
EP1.3 SF, FI, CF, RC
EP1.4 BE, UT, CS, SF, IS, CF, RC
EP1.6 FI
EP2.1 BE, UT, CS, SF, IS, CF, RC
EP2.2 BE, UT, CS, SF, IS, FI, CF, RC, VS
EP3.2 FI
EP4.1 BE, UT, CS, SF, IS, CF, RC
EP4.2 BE, UT, CS, SF, IS, CF, RC
EP4.3 BE, UT, CS, SF, IS, CF, RC